1. Field of the Invention
The present invention relates to a latch-type level converter and a receiver circuit and, more particularly, to a latch-type level converter for use in a receiver circuit in a signal transmission system, a semiconductor storage device, or the like.
2. Description of the Related Art
Recently, the processing speed required of an information processing apparatus has been steadily increasing and, along with this trend, there has developed a need to increase the speed of signal transmission within an LSI (Large Scale Integration Circuit) or between LSIs forming the information processing apparatus. For high-speed signal transmission, signals are often transmitted at low amplitude levels in order to suppress signal reflections and prevent the loss of high-frequency components.
Specifically, in recent semiconductor manufacturing technology, the device size has been decreasing and the integration level has been increasing, and the need for higher signal transmission speed, involving reducing signal amplitude levels, etc., has been increasing; with this trend, the transistors forming a latch-type level converter, for example, are each formed as a low voltage transistor by reducing the thickness of its gate oxide film. Further, if input signals having a common-mode voltage higher than the supply voltage are fed to a latch-type level converter, signal-input transistors receiving input signals are subjected to a voltage higher than their breakdown voltages.
In this case, the receiver circuit must be equipped with a circuit capable of accurately amplifying low-amplitude signals. Furthermore, depending on the system, there are cases where a common-mode input signal higher than the supply voltage is input; in view of this, there is a need to provide a latch-type level converter that can receive such a high common-mode input signal.
The prior art and its associated problem will be described in detail later with reference to relevant drawings.